Web severing device for offset printing press



Oct. 8, 1968 Filed Jan. 19, 1967 J. W. ,HALLEY 3,404,627

WEB SEVERING DEVICE FOR OFFSET PRINTING PRESS 2 Sheets-Sheet 1 mmn' IFIE.

INVENTOR BY I United States Patent ABSTRACT OF THE DISCLOSURE Astationary cutting device for severing the broken end portion of a webin connection with a web offset printing press to actuate a pressstopping mechanism sooner than otherwise.

Background and summary 0 the invention In the operation of a web offsetprinting press, a web is drawn through the press by rollers remote fromthe printing and blanket cylinders. The web travels a lengthy andcircuitous route which to some extent is determined by the printing jobbeing done. From time to time a web breaks.

The rollers drawing or pulling the web and thus placing and keeping itunder tension are located at the forward end of the press. When the webbreaks at a point rearwardly of the pulling rollers, tension upon theweb is gone back to the point of the first pair of blanket cylindersprior to the point of breaking.

Sensing means such as a photoelectric cell is commonly used to stop thepress upon the breaking of the web. Such means are generally placedadjacent to and forwardly of the various blanket cylinders in the press.The broken end of the web must be pulled free from an underlyingposition with respect to an electric eye for said eye to actuatemechanism to shut down the press. In the meantime, the first pair ofblanket cylinders prior to the break being coated with ink will tend tocause the web to adhere thereto and thus the web will become wound aboutthe lower of the blanket cylinders. As the web is pulled forwardly to bewrapped about said blanket cylinder, the end portion broken away fromthe pulling rollers is retracted by said blanket cylinder which resultsin a double layer of web becoming wrapped about said blanket cylinderand the web tends to crush the blanket about said cylinder and it mustthen be replaced. There may be considerable double wrap about saidblanket cylinder before the broken free end of the web is withdrawn froma position underlying said cell whereby said cell is actuated to causethe press to be stopped. A major loss suffered here is the loss of thetime during which the press is stopped while the blanket is beingreplaced and the web corrected.

It is an object of this invention therefore with respect to a web offsetprinting press to provide means for severing the broken end of a webprior to the time that it becomes wrapped about a blanket cylinder.

It is another object of this invention to provide a device mountedadjacent a blanket cylinder arranged and constructed to sever said webby the action of a blanket cylinder commencing to retract the broken endportion of a web free of tension.

More specifically it is an object of this invention to provide a sawtooth blade adjacent a blanket cylinder arranged to engage and sever aweb being retracted by said blanket cylinder and means for closing downthe press being actuated by said web upon its being severed whereby theblanket cylinder avoids having the free broken end portion of the webfrom becoming wrapped thereabout.

These and other objects and advantages of the invention will be setforth in the following description made in connection with theaccompanying drawings in which like 3,404,627 Patented Oct. 8, 1968reference characters refer to similarparts throughout the several viewsand in which:

FIG. 1 is a broken view in side elevation showing the subject matter ofthe invention herein in operating positron;

FIG. 2 is a fragmentary view in vertical section on an enlarged scale;

FIG. 3 is a fragmentary bottom plan view on an enlarged scale taken online 33 of FIG. 2 as indicated;

FIG. 4 is a fragmentary view in vertical section showing a detail ofoperation; and

FIG. 5 is a composite view in cross section and plan of a detail ofstructure herein.

Description of a preferred embodiment Referring to the drawings, asufficient portion of a web offset printing press 10 is shown to supportthe subject matter of the invention herein.

The structure shown comprises a pair of transversely spaced upstandingframe members 12 and 14 supporting a pair of transversely spacedoverhead rails 17 of which only one rail is shown. Said frame membersare shown having journaled therebetween a pair of blanket cylinders 19and 20 in superposed relation, and adjacent said respective blanketcylinders are printing cylinders 22 and 23. Said frame members and thecylinders journaled therebetween will be designated as Station A.

Spaced longitudinally of said upstanding frame members 12 and 14 are asimilar pair of upstanding frame members 27 and 29 having like cylindersjournaled therebetween indicated in dotted line but not designated bynumerals. Said frame members 27 and] 29 comprise Station B.

A pair of longitudinal transversely spaced horizontal rails 32 and 33are secured as by bolts 15 to said upstanding frame memberssubstantially midway their height.

Spaced between Stations A and B and journaled in bearing brackets 35depending from said rails 32 and 33 are a pair of longitudinally spacedidler or grated rollers 38 and 39.

Carried between the frame members 32 and 33 adjacent the roller 38 is atubular member 42 secured by angled brackets 44. Carried by said member42 and projecting therebeneath are sensing means 4 6 shown asphotoelectric cells and sometimes referred to as electric eyes. Thecells used here are in circuit with a mechanism to stop the operation ofthe press and said mechanism is held non-active so long as a webunderlies the cells. The circuitry involved is not essential to adisclosure of the invention herein and is not shown.

Positioned between said member 42 and said blanket cylinder 20 is a websevering device indicated generally by the numeral 50. This devicecomprises the subject matter of the invention herein.

Said device 50 comprises a cutting blade 52 having a cutting edgecomprising relatively coarse sharply pointed and preferably beveledteeth 53 on the order of saw teeth and shown on an enlarged scale inFIG. 5. Teeth of a coarseness that would run from 6-8 to the inch arequite suitable. A pair of angle brackets 54 and 55 have said bladesecured at its ends thereto as by suitable bolts and said brackets arerespectively secured to said frame members 32 and 33 by bolts 57. Saidbrackets are shown suitably angled downwardly at approximately and theplane of said blade is preferably so disposed with respect to thehorizontal.

The device is here shown adjacent. one printing station or one set ofblanket rollers. Like devices may be positioned adjacent each of thepairs of blanket cylinders present in the press.

The overhead rails 17 comprise spaced parallel members which extendsubstantially the length of the press and are here shown in brokensegments. Said rails support overhead rollers which serve 'as webguides. Indicated here are upstanding supports 60-64 respectively. Thesesupports are to be regarded as pairs of transversely spaced membershaving journaled therebetween one or more rollers 66 as indicated.

Shown being drawn through the portion of the press indicated is a web70. The direction of forward normal travel of said web is indicated byarrows.

Operation The web is drawn through the press by pulling rollersstationed at the forward end portion of the press and not here shown.Hence there is tension on the web its full length of travel.

The blanket cylinders 19 and 20 are representative of a number of suchpairs of rollers stationed in various portions of the press. The blanketcylinders have inked impressions applied thereto by the adjacentprinting cylinders and in turn make impressions or prints on either sideof the web drawn therebetween.

A representative path of the web is indicated. The web angles downwardlyfrom the blanket cylinder 20 to travel around the underside and upwardlyof the roller 38. The web is angled downwardly sufiiciently to bearfirmly against the blanket cylinder 20. The cutting device 50 ispositioned to have the web pass over the blade 52 close thereto buthaving preferably a small clearance therebetween. The photoelectric cell46 is positioned between the cutting device 50 and the roller 38.

From time to time the web breaks at some point along its path of travel.Tension or weakness may develop at some point in the web causing it tobreak. With the web broken at some point beyond Station A, the tensionupon the web will be gone and the web portion from Station A forwardlywill be in a slack condition. The cell 46 is intended to shut down thepress when a break occurs in the web. However, before said cell can betriggered to actuate the mechanism to shutdown the press, the broken endof the web must pass or be moved away from under the cell. The cell isin a non-actuating condition with respect to the press stoppingmechanism so long as a portion of a web is thereunder providing areflective surface for the beam projected by the cell.

With reference to FIG. 4, when a break occurs in the Web and the brokenend portion is slack, the blanket cylinder 20 will cause the web toadhere thereto due to the presence of ink thereon. In the absence oftension on the web, the'ink on the blanket cylinder will cause the webto adhere thereto. Hence the cylinder 20 will tend to pull and wrapabout itself the portion of the web passing thereover, and at the sametime it retracts or draws back the broken or slacked portion of the web.Thus as indicated, if this condition were permitted to continue, theblanket cylinder 20 would have a double wrap of web wound thereaboutuntil the broken end of the web was pulled free from under the cell 46.By this time there may be several layers of web material wrapped aboutthe cylinder 20 and the tension and weight of the web thereabout damagesthe blanket about the cylinder. This is a condition which occurs and isthe condition which is corrected by the invention herein.

There is not only damage to the blanket about the blanket cylinderwhereby it must be replaced, but there is a loss of time in unwindingthe web from the blanket cylinder and replacing the blanket on thecylinder. On a large press there may be involved operating time whichmay cost as much as $500 to $600 per hour. Thus the stoppage of thepress in the middle of a run means a substantial loss to the operatoreven with the stoppage representing something less than an hour of losstime.

With the installation of the device 50 herein, when the web is 'broken,the blanket cylinder 20 will commence to retract the broken or slackportion of the web as indicated in FIG. 4. However, the instant that thebroken 4 portion of the web is retracted, due to its slack condition, itis drawn about the blanket cylinder at a downward angle and is pulledinto engagement with the cutting blade 52 and upon this engagement theteeth 53 penetrate the web. Thus as the blanket cylinder 20 putspressure upon this portion of theweb in retracting it, the web isreadily and quickly severed by said blade 52. Thus the severed ends ofthe web will fall free and away from under the cell 46 and the mechanismto shut down the press will be actuated and the press will be stoppedbefore the blanket cylinder 20 completes a wrap of web thereabout. Heredamage to the blanket about the blanket cylinder is avoided. The brokenend portions of the web may be spliced together or other correctiveaction may be taken to repair the'web without the need of replacement ofthe blanket about the blanket cylinder. This type of corrective actionrequires but a few moments of time.

Thus it is seen that I have provided a very simple and yet effectivecutting device which in effect is self operative to prevent any damageto a press through the presence of abroken web.

It will of course be understood that various changes may be made in theform, details, arrangement and proportions of the parts, withoutdeparting from the scope of applicants invention which, generallystated, consists in a device capable of carrying out the objects aboveset forth, of the parts and combinations of parts disclosed and definedin the appended claims.

What is claimed is:

1. In connection with a web offsetting printing press having a blanketcylinder, a press stopping means in closely spaced relation to saidblanket cylinder and a web passing over said blanketcylinder inoperative rela tionship with said stopping means, a web severing devicecomprising an elongated cutting blade extending transversely of saidpress and of said web under the run of said web,

means carried by said press rigidly supporting said blade andpositioning the same adjacent the side of said blanket cylinder beyondwhich said web passes and having said stopping means in close proximitythereto, said blade being at a height to have said web under normaloperating tension pass thereover with just sufiicient clearance to avoidengagement therewith,

said blade having a saw toothed leading edge portion beingsufiiciently'coarse and sharp to holdingly engage and sever said web andbeing disposed in a sufficiently upwardly angled position in thedirection of the normal travel of said web to engage and hold said webagainst retraction thereof upon the release of tension therefrom and theconsequent sagging of said web upon said saw toothed portion,

said blanket cylinder upon said release of tension from said web urgingthe retraction of said web against its hold by said saw toothed portionfor severance of said Web, and

said stopping means being actuated by said severance of said web.

2. The structure set forth in claim 1, wherein a pair of transverselyspaced frame held arms rigidly hold said blade in said position.

References Cited UNITED STATES PATENTS 1,135,416 4/1915 Walkup 1012281,951,433 3/1934 Millingar et al 8360 2,201,180 5/1940 Jordan 83-603,011,790 12/1961 Brunson 101227 3,203,346 8/1965 Norton et a1. 101-2173,317,734 5/1967 Martin 226-11 ROBERT E. PULFREY, Primary Examiner. C.D. CROWDER, Assistant EXalIli/IGI'.

